The Wraith clones and Homura all said she was afraid to destroy it because she belived it was her one link to Madoka. She's running from the sheild because she's tempted by loniliness to just stay in there with Gretchen just to be with Madoka. This fear is proven wrong because it's also Madoka's desire to for her to remember her.
In terms of Kyubey, she has no reason to worry. He just thinks she's a crazy homeless girl. Curiosity is illogical and nothing about Homura is logical.>>13242
Your pet theory is wrong. Everything balances out in the end. Kyubey, Sayaka, and Kyouko all say this. The issue was Homura over came hope and despair. Her soul gem was tainted with love, not curses. In this respect, her will overcame Madoka's.
AI YO isnt just a meme. Love is what Homura feels for Madoka and it's through love she continues to suffer. There's no hope or despair that can overcome it, because as stated, love is the strongest human emotion. That's meant to be taken literally. I dont know what's coming next, but it's seems like it's going to be pretty gay.